The present invention relates generally to roll-to-roll manufacturing, and more particularly, to an apparatus and system for roll-to-roll processing.
Roll-to-roll processing, reel-to-reel processing or web-handling processing, which was widely used in textile and paper printing industries in the past, has become popular today in manufacturing flexible substrates. A roll-to-roll processing system relates to one using rollers for controlling transmission direction, tension and speed of a roll of, for example, flexible material in a continuous manufacturing process. Such a continuous manufacturing process has the advantages of manpower saving, manufacturing cost reduction and compatibility of manufacturing systems with materials of different dimensions. A flexible substrate provides a base for a flexible circuit board or a flexible flat panel display. As compared to their rigid counterparts, flexible circuit boards and flexible flat panel displays are generally thinner and more light-weight, and allow three-dimensional assembly with other circuit boards or devices. However, the flexible circuit boards and flat panel displays cost more than their rigid counterparts. To lower the cost, an interest in the roll-to-roll processings for flexible substrates is rapidly increasing.
Conventional processes for roll-to-roll manufacturing are often designed in a double-side contact manner, where both sides of a roll of flexible material will contact rollers during processing. Processes based on double-side contact may facilitate tension control and offset control so as to ensure manufacturing quality. Such processes may incur contamination to a working surface of the roll of flexible material. One solution to overcome the contamination issue is to clamp the edges of the roll of flexible material. However, the clamping method may incur other issues such as transmission instability and the difficulty in precision control. Another solution is to rearrange the processing stations required for a double-side process in a closed-loop to emulate a single-side process, where only one side of a roll of flexible substrate is allowed to contact rollers. However, such a method may incur other issues such as inconsistence in the processing stations. It is thus desirable to have a roll-to-roll process that is designed in a single-side contact manner, uses economy of scale for mass production, and maintains consistence in various processing stations.